Should I sand powder coating?

I have two questions related to some rock sliders I just got my hands on. They are already powder coated and in practically new condition, but have some chipped/flaking from getting banged up in transport. I don't care since the chips are on the underside and my research here pretty much says to patch up with Rustoleum Hammered Metal Finish. (side note, I'm going to paint the skid plate with the same Hammered Metal finish) My main concern is to account for any possible issues with rust and keep it fairly clean.

1. Should I sand down the banged up parts before painting over? I don't want to damage the powder coat, but not sure what I need to do to make sure the Rustoleum sticks. Note: there isn't any surface rust on the dinged up parts, its all very clean/new.

2. Should I worry about any surface rust on the frame before bolting on? My truck has been through one New England winter and has some nice surface rust on the frame already. Do I need to address this prior to bolting on the sliders? If so, can I get by with a power wash and Rustoleum matte black or do I need to do something fancy?

I don't want to "trap" any rust that may get worse and cause issues, but I don't want to go pay someone hundreds of bucks to clean up the frame after less than a year.

As always, thanks in advance for all the help and info.

 

Here is a close up of the damage. I think I'm not gonna sand it and just cover it up with the hammered finish Rustoleum.

 

Do not paint over powder coat that makes no sense. And yes you should address the frame rust prior im doing the same thing now. It just takes time. The rust will spread everywhere if not taken care of.

 

You can paint over powdercoat. You cannot powdercoat over paint. Unless you plan on sending it to be re-powdercoated you really don't have any choice.

Use this to paint it. It's best stuff out there for over the counter. You can get it at Advanced Auto Parts as well as a bunch of other places. https://www.duplicolor.com/products/truckBedCoating/